The shooting began on Wednesday morning when Hamas fighters dropped mortars near Israeli military vehicles operating inside the Gaza strip. An Israeli tank fired back.

Since then Hamas has fired 12 mortars while Israel has carried out four waves of airstrikes and fired barrages of tank shells, according to the Israel Defence Forces (IDF).

The only reported casualty was a 54-year-old Palestinian woman named Zeina Al-Amour who was killed by Israeli tank fire on Thursday, according to Palestinian medics.

Israeli forces routinely operate on a narrow strip of land inside the Gaza border and Hamas usually ignores the incursion and refrains from firing. But something changed this week and Hamas responded more aggressively.

The IDF has located two tunnels in the last month and Lt Col Lerner said Hamas “may have changed their strategy because they feel they may lose these assets”.

Israel said a combination of technology, intelligence and groundwork led to the discovery of the the two tunnels. It also emerged that Israel’s security services captured a Hamas operative with knowledge of the tunnel-building programme, which may have aided the breakthrough.

Finding Hamas’s tunnels has been a top priority for Israeli forces this year.

Hamas said Israel’s incursions into Gaza this week were deeper than usual and it opened fire in defence of its territory. “We are not calling for a new war, but we will not under any circumstances accept these incursions,” said Ismail Haniyeh, the group’s political leader in Gaza.

Israel says it maintains a 100m buffer zone inside Gaza but Palestinians claim that Israeli troops often venture much further and shoot at anyone who comes near the border.

Both Israel and Hamas said they had no interest in another full-blown conflict. Egypt brokered a ceasefire between the two sides in 2014 and its government is trying to help prevent another escalation.

More than 2,100 Palestinians were killed in the last war alongside 66 Israeli troops and six civilians.